A heat enabled magnetic media having a composite magnetic recording layer structure that includes first and second magnetic layers and an exchange coupling layer sandwiched between the first and second magnetic layers. The exchange coupling layer has a reduced Curie temperature that allows the magnetic layers to become decoupled a lower temperature. This reduced Curie temperature can be achieved the addition of an alloying element such as Ni or Cu into the exchange coupling layer. Therefore, the exchange coupling layer can be constructed of an alloy such as FePtNi FePtCu, and the magnetic layers can be constructed of a material such as FePt.
Legal claims defining the scope of protection, as filed with the USPTO.
1. A magnetic media for data recording, comprising: a first magnetic layer having a first curie temperature; a second magnetic layer hay hag* a second curie temperature; and an exchange coupling layer having a third curie temperature between the first and second magnetic layers, wherein the third curie temperature is lower than the either of the first and second Curie temperatures; wherein the first magnetic layer comprises a FePt alloy having a highly ordered crystalline structure, the second magnetic alloy comprises a FePt alloy having a lo o moderately ordered crystalline structure and the exchange coupling layer comprises an alloy that includes Fe, Pt and Ni.
2. The magnetic media as in claim 1 wherein the exchange coupling layer comprises an alloy that includes Ni.
3. The magnetic media as in claim 1 wherein the exchange coupling layer comprises a FePtNi alloy.
4. The magnetic media as in claim 1 wherein each of the first and second magnetic layers comprise a FePt alloy and the exchange coupling layer comprises a FePtNi alloy.
5. The magnetic media as in claim 1 wherein the first magnetic layer has a thickness of 2-5 nm, the second magnetic layer has a thickness of 3-10 nm and the exchange coupling layer has a thickness that is not greater that 1 nm.
6. The magnetic media as in claim 1 wherein the exchange coupling layer comprises a FePtNi alloy having a Ni concentration of 30 to 50 atomic percent.
7. The magnetic media as in claim 1 wherein the first magnetic layer comprises an alloy that includes Cu.
8. The magnetic media as in claim 1 wherein the first magnetic layer comprises an alloy that includes Fe, Pt and Cu.
9. The magnetic media as in claim 1 wherein the exchange coupling layer comprises an alloy that includes Fe, Pt and Cu.
10. The magnetic media as in claim 1 wherein each of the first and second magnetic layers comprises FePt and the exchange coupling layer comprises FePtCu.
11. The magnetic media as in claim 1 wherein the first Curie temperature is 40-60 degrees Kelvin higher than an ambient temperature.
12. The magnetic media as in claim 1 wherein the third Curie temperature is 40-60 degrees Kelvin lower than either of the first and second Curie temperatures.
13. The magnetic media as in claim 1 wherein the exchange coupling layer comprises an alloy that includes Cr.
14. A magnetic media for data recording, comprising: a first magnetic layer having a first curie temperature; a second magnetic layer having a second curie temperature; and an exchange coupling layer having a third curie temperature between the first and second magnetic layers, wherein the third curie temperature is lower than wherein the third Curie temperature is 40-60 degrees Kelvin above an ambient temperature and the and the third Curie temperature is 40-60 degrees lower than either of the first and second Curie temperatures.
15. A magnetic data recording system comprising: a housing; a magnetic media mounted within the housing; a slider held within the housing and arranged for movement adjacent to a surface of the magnetic medium, the slider having mounted thereon, a write head, a read head and a heating element for locally heating the magnetic media; wherein the magnetic media further comprises: a first magnetic layer having a first curie temperature; a second magnetic layer having a second curie temperature; and an exchange coupling layer having a third curie temperature sandwiched between the first and second magnetic layers, wherein the third curie temperature is lower than the either of the first and second Curie temperatures; wherein the first magnetic layer comprises a FePt alloy having a highly ordered crystalline structure, the second magnetic alloy comprises a FePt alloy having a low to moderately ordered crystalline structure and the exchange coupling layer comprises an alloy that includes Fe, Pt and Ni.
16. The magnetic data recording system as in claim 15 wherein the exchange coupling layer comprises an alloy that includes Ni.
17. The magnetic data recording system as in claim 15 wherein the exchange coupling layer comprises a FePtNi alloy.
18. The magnetic data recording system as in claim 15 wherein each of the first and second magnetic layers comprise a FePt alloy and the exchange coupling layer comprises a FePtNi alloy.
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March 9, 2012
January 14, 2014
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